I had my left knee repaired two years ago.I had three tears in my meniscus and also chondromalacia of the femoral condyle.Don't know how any of this happened,maybe wear and tear over time,maybe from impact of jumping off a trailer,just don't really know.Don't remember any one event that I can say caused the damage.Two years later,I say I did the right thing getting it fixed.I does take time to completely heal,but it's much better than feeling pain everyday.I did have a good doctor and I feel like nothing ever happened.